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You are here: Home / Publications / Periodicals / Natural Outlook / Spring 2010 / Science and Technology Help Keep the Air Clean

Science and Technology Help Keep the Air Clean

The TCEQ employs the latest technology and scientific methods to improve the quality of the air in Texas. (Natural Outlook, Spring 2010)


The TCEQ has the unique challenge of authorizing, regulating, and monitoring industry in a state with one of the most developed and diverse economies in the nation, all the while protecting human health and the environment. One of the best ways to meet this challenge is to employ the latest technology and scientific methods to ensure that each chemical emitted in Texas is kept at or below a level that could potentially cause adverse health and welfare effects.

GasFindIR Camera Technology

The TCEQ was one of the first state agencies in the country to use GasFindIR camera technology to monitor air quality. Originally developed for the military, the camera is a handheld remote sensing device based on infrared thermographic principles, with the special capability of making hydrocarbon emissions visible under certain ambient conditions.

Man looking through viewfinder of IR camera, with reflection of refinery in the camera lens

The camera—which serves as a screening tool to assist the agency in activities such as facility and reconnaissance investigations and mobile monitoring—has proved to be highly effective in the detection of VOC emissions from leaks and previously unidentified or unrecognized sources. With the knowledge gained from the use of the camera, the TCEQ has improved emissions inventories and enhanced regulations to address these emissions, focusing efforts on real air quality solutions with real results. The use of this technology has resulted in thousands of tons of reduced VOC emissions.

Effects Screening Levels

The TCEQ uses scientific data to establish effects screening levels (ESLs) and reference values (ReVs)—health-protective levels of exposure for air pollutants. ESLs assist the TCEQ in permitting safe emission levels from industry and both ESLs and ReVs are used in confirming that the air is safe to breathe through monitoring evaluations.

In 2006, the TCEQ Toxicology Division finalized new guidelines for developing ESLs and ReVs. A stringent external scientific peer review by world-renowned experts and two rounds of public comment resulted in a scientifically defensible method of developing chemical-specific guidelines that are protective of both short- and long-term human health and welfare.

ESLs developed using the TCEQ’s 2006 guidelines have garnered attention from other states and countries as being
among the most scientifically sound health-based assessments.

“A case in point is 1,3-butadiene,” says Lindsey Jones of the TCEQ Toxicology Division. “In 2008, the Ontario Ministry of Environment deemed the TCEQ ESL the most defensible assessment of health risk over the assessments made by the U.S. EPA, the World Health Organization, and other state and national organizations.”

Learn more about Effects Screening Levels.

Air Pollutant Watch List

The Air Pollutant Watch List (APWL) is a list of small geographic areas in Texas (typically smaller than a zip code area) where the TCEQ has determined that specific air pollutants have been measured at levels of concern.

Each year, the TCEQ Toxicology Division reviews ambient air monitoring data from approximately 74 monitoring sites across the state and data gathered during mobile monitoring activities. Monitored concentrations of pollutants are then compared to the TCEQ’s health-protective comparison values, such as ESLs and ReVs. After an opportunity for public comment, areas of concern are placed on the APWL. The agency then works with area facilities to achieve emissions reductions in watch list areas through enhanced monitoring, permit reviews, investigations, voluntary facility actions, and enforcement.

There are currently 11 APWL areas in 10 Texas counties. As a result of agency efforts to reduce emissions of compounds of concern in APWL areas, monitored concentrations for many of these compounds are trending downward. Since 2007, 12 pollutants have been removed from the list, and no areas have been added.

Learn more about the Air Pollutant Watch List.

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